Wave Action on Groups of Vertical Circular Cylinders

Research on the motions in waves has a very important meaning for floating offshore platforms, since they must be stationary in the sea. The theoretical calculations of hydrodynamical forces upon such platforms moving in waves are necessary for correct theoretical predictions of their motions. As a first step, in this paper, is developed a method to calculate the wave forces acting upon groups of vertical circular cylinders, as a simple model of floating platforms of several columns, fixed in waves with finite draft and infinite draft. This method takes into account the hydrodynamical interaction effect, between cylinders due to the diffraction waves by each cylinder. Numerical results by this method for the wave forces on 2 or 3 cylinders, show that the interaction effect upon surging forces is not necessarily small except for large wave length range compared with the cylinder diameter. The numerical results are in good agreement with measured ones obtained by comparatively simple experiment.